The present invention relates to a sensing edge, and more particularly, to a sensing edge that can be installed on a door with the conductors placed on the right or the left hand side of the door, either toward the end of the sensor or away from the end to allow for a cylinder lock, and that has extensions on the ends of the sheath that are capable of being trimmed to allow for a custom fit on the door.
Sensing edges for doors are generally well known. Such sensing edges generally include an elongated outer sheath in which a force sensing switch is positioned. Upon the application of force to the sheath, the force sensing switch actuates suitable control circuitry for controlling the movement of the door. The force sensing switch positioned within the sheath typically comprises a pair of flexible, spaced, electrically conducting sheaths positioned on the upper and lower sides of a layer of non-conducting foam having a plurality of openings extending therethrough from the upper to the lower side. Upon application of force to the sheath, either or both of the conductive sheaths are deflected into electrically conductive engagement with each other, to thereby complete an electrical connection and actuate suitable control circuitry for controlling the door.
Conventional sensing edges, including the above described force sensor, are not as versatile as that contemplated in the present invention. A common problem with conventional sensing edges is their difficulty of installation. Since the conductors exit the sheath through a fixed aperture that is located either on the end surface of the sheath or on the top edge of the sheath, the installer of the sensing edge must determine, before installation, whether he is working with circuitry that is going to be placed on the right hand side of the door, or on the left hand side. If the installer goes out to the job site and in the middle of an installation discovers that for some reason the control circuitry must be located on a different side of the door than was originally planned, he must then take the sensing edge that is currently in his possession and exchange it for another sensing edge which has the conductors placed on the other side. The reason for this is that since conductors generally exit the sheath from an end, the sensing edge is either a right-handed or left-handed edge.
Another common problem with conventional sensing edges is the inability to use a cylinder lock on doors upon which a sensing edge is installed. Because conductors exit the sheath through an aperture that it located either on the end surface of the sheath or on the top edge of the sheath, the conductors tend to obstruct the operation of a cylinder lock.
Yet another common problem with conventional sensing edges is the difficulty of custom fitting a conventional sensing edge to a door which may vary from a standard length. Unless the door is of a standard size, a custom order has to be placed in order to fit the door with a conventional sensing edge of a specific length.
The present invention is directed to a sensing edge for a door for sensing objects that come into contact with the sensing edge during door closing. The sensing edge in the present invention overcomes the problems inherent in the prior art. Multiple apertures are located in the top of the sheath so that the installer of the sensing edge can place the conductors through any one of the apertures. This results in increased versatility since it allows the installer to extend the conductors through the aperture position proximate either side surface of the door, making the sensing edge bilateral. The installer may also choose to extend the conductors through apertures located away from the ends of the sensing edge to allow for the use of a cylinder lock with the door. Also, extensions located on the ends of the sheath are capable of being trimmed right to the door guide, allowing a custom fit of the sensing edge to the door.
Briefly stated, the present invention comprises a sensing edge for causing a closing door to open by actuating a device upon force being applied to the sensing edge. The door has a leading edge surface, a first lateral side surface, and a second lateral surface, the first and second lateral side surfaces being oppositely disposed and the door being mounted for movement through a range of motion. The sensing edge comprises an elongate outer sheath which is positioned adjacent to the leading edge surface of the door and is compressible upon application of external pressure. The sheath comprises a first wall including first and second oppositely disposed surfaces and first and second oppositely disposed ends. An inner wall extends proximate the first wall, being secured to the first wall such that the first wall and the inner wall define a first cavity. The inner wall has a first aperture extending therethrough. A top wall extends generally parallel to and spaced from the inner wall. The top wall is secured to the inner wall, the top wall and the inner wall defining a second cavity. The top wall has a plurality of top wall apertures extending therethrough. An elongate sensor is positioned within the first cavity for detecting an external force applied to the sheath. The sensor extends substantially along the entire length of the sheath between the first and second surfaces and between the first and second ends. At least one electrical conductor is in electrical communication with the sensor. The conductor extends through and is sealingly maintained within the first aperture. The conductor extends into the second cavity and is capable of extending through any one of the top wall apertures for connection with the device for controlling actuation of the door when the sensor detects application of force to the sheath.